Experimental Investigation of Electropolishing in Ethylene Glycol-NaCl Electrolyte for Surface Integrity of Nitinol Cardiovascular Stents

Abstract

In order to improve the surface integrity of nitinol cardiovascular stents, this paper presented the method of electropolishing nitinol cardiovascular stents by adding distilled water of different concentration into ethylene glycol - sodium chloride electrolyte to find the optimal electrolyte composition and to investigate the change of surface chemical composition. The I-V curves and surface roughness were measured to determine the optimal polishing voltage range. The optimal polishing voltage and the composition and concentration of electrolyte were obtained by data analysis. Surface integrity of nitinol cardiovascular stents has also improved significantly. In addition, Titanium dioxide film was formed on the surface of the nitinol cardiovascular stents, which played an important role in improving the biocompatibility of the stents.

Keywords

• nitinol cardiovascular stents
• electropolishing
• surface integrity
• process technology